This is a randomized, double-blind, parallel group, active-controlled trial of eighteen months' duration and a total of 72 patients. The study will be performed at two sites, the University of Utah GCRC and the University of Colorado GCRC. Patients with NYHA class II-IV heart failure due to idiopathic dilated cardiomyopathy will be treated with either bucindolol or metoprolol to determine changes in myocardial gene expression associated with either of these drugs. Changes in gene expression associated with alterations in myocardial function and remodeling are also under study. If bucindolol or metoprolol proves to lower cardiac adrenergic drive, then the relationship of this effect to changes in myocardial gene expression will be defined. If bucindolol or metoprolol lowers activity of the renin-angiotensin system, then the relationship of this effect will also be correlated with changes in myocardial gene expression. Milrinone is a phosphodiesterase inhibitor and the use of this agent will enable the investigators to determine if the effects of bucindolol are enhanced by this drug, suggesting that bucindolol may also act through a cyclic-AMP-dependent mechanism. This study is in its earliest phases but no data are mature enough to report.